Add docs landing page back (#1537)

## Description

This reverts commit 18bc6b05e10df44083ed67010fc62ea9b0a2efd1 in prep for bringing the blog
back to docs.

## Type of change

- [x] 🗺️ Documentation

docs/docs/intro.md

@@ -1,8 +1,4 @@
----
-slug: /
----
-
-# Corso introduction
+# Introduction
 
 ## Overview
 

docs/docusaurus.config.js

@@ -68,13 +68,19 @@ const config = {
     /** @type {import('@docusaurus/preset-classic').ThemeConfig} */
     ({
       navbar: {
-        title: 'Docs',
+        title: '',
         logo: {
           alt: 'Corso Logo',
           src: '/img/corso_horizontal_logo.svg',
           srcDark: 'img/corso_horizontal_logo_white.svg',
         },
         items: [
+          {
+            type: 'doc',
+            docId: 'intro',
+            position: 'left',
+            label: 'Docs',
+          },
           {
             href: 'https://github.com/alcionai/corso',
             label: 'GitHub',
@@ -90,6 +96,15 @@ const config = {
           height: 60,
         },
         links: [
+          {
+            title: 'Resources',
+            items: [
+              {
+                label: 'Docs',
+                to: '/intro',
+              },
+            ],
+          },
           {
             title: 'Community',
             items: [
@@ -140,6 +155,15 @@ const config = {
         },
       },
 
+      image: 'img/cloudbackup.png',
+
+      metadata : [
+        {name: 'twitter:card', content: 'summary_large_image'},
+        {name: 'twitter:site', content: '@corsobackup'},
+        {name: 'twitter:title', content: 'Corso Documentation: Free, Secure, and Open-Source Backup for Microsoft 365'},
+        {name: 'twitter:description', content: 'Documentation for Corso, an open-source tool, that protects Microsoft 365 data by securely and efficiently backing up all business-critical data to object storage.'},
+      ],
+
       prism: {
         theme: lightCodeTheme,
         darkTheme: darkCodeTheme,

docs/src/components/HomepageFeatures/index.js

@@ -0,0 +1,61 @@
+import React from 'react';
+import clsx from 'clsx';
+import styles from './styles.module.css';
+
+const FeatureList = [
+  {
+    title: 'Secure',
+    Svg: require('@site/static/img/security.svg').default,
+    description: (
+      <>
+        Corso provides secure data backup that protects customers against accidental data loss, service provider downtime, and malicious threats including ransomware attacks.
+      </>
+    ),
+  },
+  {
+    title: 'Robust',
+    Svg: require('@site/static/img/data.svg').default,
+    description: (
+      <>
+       Corso, purpose-built for M365 protection, provides easy-to-use comprehensive backup and restore workflows that reduce backup time, improve time-to-recovery, reduce admin overhead, and replace unreliable scripts or workarounds.
+      </>
+    ),
+  },
+  {
+    title: 'Low Cost',
+    Svg: require('@site/static/img/savings.svg').default,
+    description: (
+      <>
+       Corso, a 100% open-source tool, provides a free alternative for cost-conscious teams. It further reduces storage costs by supporting flexible retention policies and efficiently compressing and deduplicating data before storing it in low-cost cloud object storage.
+      </>
+    ),
+  },
+];
+
+function Feature({Svg, title, description}) {
+  return (
+    <div className={clsx('col col--4')}>
+      <div className="text--center">
+        <Svg className={styles.featureSvg} role="img" />
+      </div>
+      <div className="text--center padding-horiz--md">
+        <h3>{title}</h3>
+        <p>{description}</p>
+      </div>
+    </div>
+  );
+}
+
+export default function HomepageFeatures() {
+  return (
+    <section className={styles.features}>
+      <div className="container">
+        <div className="row">
+          {FeatureList.map((props, idx) => (
+            <Feature key={idx} {...props} />
+          ))}
+        </div>
+      </div>
+    </section>
+  );
+}

docs/src/pages/index.js

@@ -0,0 +1,40 @@
+import React from 'react';
+import clsx from 'clsx';
+import Layout from '@theme/Layout';
+import Link from '@docusaurus/Link';
+import useDocusaurusContext from '@docusaurus/useDocusaurusContext';
+import styles from './index.module.css';
+import HomepageFeatures from '@site/src/components/HomepageFeatures';
+
+function HomepageHeader() {
+  const {siteConfig} = useDocusaurusContext();
+  return (
+    <header className={clsx('hero hero--primary', styles.heroBanner)}>
+      <div className="container">
+        <h1 className="hero__title">{siteConfig.title}</h1>
+        <p className="hero__subtitle">{siteConfig.tagline}</p>
+        <div className={styles.buttons}>
+          <Link
+            className="button button--secondary button--lg"
+            to="quickstart">
+            Corso Quickstart - 5min ⏱️
+          </Link>
+        </div>
+      </div>
+    </header>
+  );
+}
+
+export default function Home() {
+  const {siteConfig} = useDocusaurusContext();
+  return (
+    <Layout
+      title={`${siteConfig.title}`}
+      description="Documentation for Corso, a free, secure, and open-source backup tool for Microsoft 365">
+      <HomepageHeader />
+      <main>
+        <HomepageFeatures />
+      </main>
+    </Layout>
+  );
+}

docs/src/pages/index.module.css

@@ -0,0 +1,25 @@
+/**
+ * CSS files with the .module.css suffix will be treated as CSS modules
+ * and scoped locally.
+ */
+
+.heroBanner {
+  padding: 4rem 0;
+  text-align: center;
+  position: relative;
+  overflow: hidden;
+  --ifm-hero-text-color: #ffffff;
+  --ifm-color-primary: #4f46e5;
+}
+
+@media screen and (max-width: 996px) {
+  .heroBanner {
+    padding: 2rem;
+  }
+}
+
+.buttons {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+}